Perineum developmental defects

Question 1

Problems of Uterus Midline Fusion

Answer 1

• Double uterus
  
  • double vagina
  • single vagina
• Bicornuate
  
  • Bicornuate with rudimentary horn
• Septate Uterus
  
  • Septum: Endometrium sparse, not ideal for implantation
  • Unicornuate uterus

Question 2

Hypospadias

Answer 2

• Failure of urethral folds to fuse results in extra urethral orifice on ventral aspect of shaft of penis
• Failure of both urethral folds & labioscrotal swellings to fuse results in perineal hypospadias

Question 3

Epispadias

Answer 3

• Urethra opens on dorsal surface

Question 4

Urachal anomalies

Answer 4

• Urachal cyst: lumen in mid-portion of allantois remains patent
  
  • may become infected
• Urachal sinus: lumen of allantois remains continuous with umbilicus or bladder
  
  • may have discharge from umbilicus
• Urachal fistula
  
  • entire allantois remains patent
  • urine may discharge from umbilicus

Question 5

Anorectal anomalies

Answer 5

• Persistent Cloaca:
• Anal Stenosis:
• Membranous Anal Atresia:
• Anal Agenesis: septum
• Rectal Atresia:

Question 6

Persistent Cloaca

Answer 6

failure of urorectal septum to meet cloacal membrane & divide cloaca into urogenital and anal parts

Question 7

Anal Stenosis

Answer 7

Urorectal septum grows slightly to the dorsal aspect resulting in a narrowed anal canal

Question 8

Membranous Anal Atresia

Answer 8

urorectal septum grows normally but anal membrane does not perforate

Question 9

Anal Agenesis

Answer 9

Anal canal opens into perineum as a fistula due to a faulty development of urorectal septum

• most common
• rectum ends above puborectalis, typically with a fistula to the vagina in females or the urethra in males
• faulty division of cloacal membrane by urorectal septum

Question 10

Rectal Atresia

Answer 10

• Rectum not united from Anal Canal
• May be due to failure to recanalise or, more often, defective blood supply during developmen